Answer:
4g of the radioactive element present
Explanation:
Radioactive elements are atoms that are unstable in normal conditions and are converted in another different atoms.
1 half life express the time that is need to decay the half of the initial amount of the radioactive element.
If initially we have 8g of the radioactive element, after 1 life we will have 8g/2 =
4g of the radioactive element present
How many molecules are in 42.3g sample of water, H2O?
Answer: There are 14.152 molecules in 42.3 g sample of water, [tex]H_{2}O[/tex].
Explanation:
According to the mole concept, 1 mole of every substance contains [tex]6.022 \times 10^{23}[/tex] atoms.
As mass of water (molar mass = 18 g/mol) is given as 42.3 g. Therefore, moles of water are as follows.
[tex]No. of moles = \frac{mass}{molar mass}\\= \frac{42.3 g}{18 g/mol}\\= 2.35 mol[/tex]
Hence, molecules of water are calculated as follows.
[tex]2.35 \times 6.022 \times 10^{23} molecules\\= 14.152 molecules[/tex]
Thus, we can conclude that there are 14.152 molecules in 42.3 g sample of water, [tex]H_{2}O[/tex].
Neptune _____.
is a terrestrial planet
has a nearly horizontal axis
was discovered by mathematical calculations
is the largest planet in the solar system
Answer:
C. Was Discovered by Mathematical calculations
Explanation:
Terrestrial Planets are Inner Planets (Mercury,Venus,Earth,Mars) and Neptune is an ice giant or gas giant, Neptune is also not the largest planet in the solar system, I believe that's Jupiter. I don't know for sure if Neptune has a horizontal axis but my best guess is C. I hope this helps! :^)
Humans rely on water for
Answer:
almost everything
Explanation:
PLS HELP ME WILL GIVE BRAIN THINGYYYYY
Answer:
C, when the ball lands it will have the least amount potential energy.
Explanation:
here is a picture that should help you.
why is Cu+O=2CuO unbalanced
Answer:
because the product of CuO contains 2 molecules so it is unbalanced
Explanation:
to balance it 2Cu+2O=4CuO now it is balanced
A base is a substance which neutralizes an acid. Which of these substances is not a base?
A. aqueous ammonia
B. sodium chloride
C. sodium carbonate
D. calcium oxide
Among these, sodium chloride is a substance which is not a base, therefore option (b) is correct.
What do you mean by a base in a chemical reaction?A base is a chemical species that donates electrons, accepts protons, or releases hydroxide (OH-) ions in aqueous solution. A base is a molecule or ion able to accept a hydrogen ion from an acid.
A strong base completely dissociates into its ions in water. Bases react vigorously with acids and organic matter. Bases react in predictable ways with pH indicators.
A base substance is a solution that has a pH level of more than 7. Bases react with acids to form salts which is called neutralization reaction.
Among these since sodium chloride is not a base, hence option(b) is correct.
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Calculate the molar solubility of aluminum hydroxide (AlOH)3) in a 0.027M solution of aluminum nitrate (Al(NO3)3). The Ksp of AlOH)3 is 2.0x10-32.
Answer:
s = 5.22x10⁻⁹ M
Explanation:
Let's write the equilibrium reaction for this compound:
Al(OH)₃ <-------> Al³⁺ + 3OH⁻ Ksp = 2x10⁻³²
To get the solubility, we need to write the equilibrium expression:
Ksp = [Al³⁺] [OH⁻]³
Al(OH)₃ does not contribute to the equilibrium expression, because is a solid compound. Now, according to this, we have the following:
Al(OH)₃ <-------> Al³⁺ + 3OH⁻
I. 0 0
E. s 3s
Replacing into the Ksp expression:
2x10⁻³² = (s) (3s)³
2x10⁻³² = s * 27s³
2x10⁻³² = 27s⁴
s = ⁴√2x10⁻³² / 27
s = 5.22x10⁻⁹ MThis would be the solubility of the compound.
Hope this helps
50 POINTS!!!
When writing a chemical reaction equation, what does the arrow ( ---> ) represent?
A. the reactants are making the products
B. the direction of the chemical equation
C. the chemical reaction cannot be reversed
D. all of the above
The condition or progress of a reaction is represented by reaction arrows. The chemical reaction arrow is a single straight arrow that points from the reactant(s) to the product(s) and by-products, as well as side products.
I think this should help you find the answer more easy!
How could the amount of ice cover at the poles be indirectly affected by an increase in evaporation near the equator? Explain.
Answer:
The factors that determine the extent of the ice cover at the poles are the temperature, the winds and the ocean currents. The Artic Ocean sea ice cover is observed to change more in response to a changes in temperature while the Antarctic sea ice cover change more with changes in the wind and ocean currents
Increased evaporation at the equator will come about as a result of rising temperatures combined with the high temperatures of the summer can result in a reduction in the amount of ice cover in the North pole oceans, while the high evaporation rate can lead to higher ocean water circulation rate between North and South poles and the equator such that the ice cover in Antarctica
Therefore, an increase in evaporation near the equator will decrease the ice cover at the poles
Explanation:
c) Mercury is solid at room temperature....True Or False
Answer:
true
Explanation:
Because Mercury can be solidified when its temparature us brought to its freezing point. However, when returned to room temparature conditions, mercury does not exist in solid state for long, and returns back to its more common liquid form.
which statement is true concerning the Haber Process?
A.
It is a process for the synthesis of nitrogen gas.
B.
It is a process for the synthesis of ammonia.
c.
It is a process for the synthesis of methane.
D.
It is a process for the synthesis of carbon monoxide.
E.
It is a process for the synthesis of carbon dioxide.
Answer: the answer is B The Haber Process is used in the manufacturing of ammonia from nitrogen and hydrogen, and then goes on to explain the reasons for the conditions used in the process. The process combines nitrogen from the air with hydrogen derived mainly from natural gas (methane) into ammonia.
Explanation: Mark as brainliest if it helped!!
How many moles are there in 8.25 x 10^26 molecules of methane (CH4)?
Answer:
i dont know
Explanation:
because i dont know 45
A vessel contained N2, Ar, He, and Ne. The total pressure in the vessel was 1100 torr. The partial pressures of nitrogen, argon, and helium were 110, 250, and 400 torr, respectively. The partial pressure of neon in the vessel was __________ torr.
A) 420 B) 340 C) 200 D) 280 E) 760
Answer:
Partial pressure Ne = 340 Torr
Option B
Explanation:
Gases contained in the vessel:
N₂, Ar, He, Ne
One of Dalton's law for gases determine this:
In a mixture of gases contained in a vessel, total pressure of the system must be the sum of partial pressure of each gas.
Total pressure = 1100 Torr
Let's replace:
Partial pressure N₂ + Partial pressure Ar + Partial pressure He + Partial pressure Ne = 1100 Torr
Partial pressure Ne = 1100 Torr - Partial pressure N₂ - Partial pressure Ar -Partial pressure He
Partial pressure Ne = 1100 Torr - 110 Torr - 250 Torr - 400 Torr
Partial pressure Ne = 340 Torr
what is the mass of 4 moles of almunium atom
Answer:
108 grams
Explanation:
A sample of helium has a volume of 3.49 L at 741 mmHg. What would be the volume if the pressure
were changed to 760 mmHg at the same temperature?
show work
P1: 741 mmHg
V1: 3.49 L P1 x V1 / P2= (741 mmHg) (3.49 L) / 760 mmHg = 3.40 L
P2: 760 mmHg
V2: ? L
Define activation energy.Activation energy is Define activation energy.the energy barrier that must be surmounted in order for the reactants to transform into products.the energy difference between the reactants and the products.the energy released by the reactants while transforming into products.the energy released by the products while transforming into reactant
Answer:
the energy barrier that must be surmounted in order for the reactants to transform into products.
Explanation:
When we draw a reaction profile, there is always a hump that is found between the reactants and products. This hump is called the activation energy.
The activation energy of a reaction stands as a sort of barrier between reactants and products which must be surmounted before the reactants are converted into products.
Only reactants that possess the activation energy can be converted from reactants to products.
____Na + ____Cl2 ---> ____NaCl
how many moles of gold is 9.75 x 10^24 atoms?
Answer:
1 Answer. You use the fact that 1 mole of any substance contains exactly 6.022⋅1023 atoms or molecules of that substance - this is known as Avogadro's number. In your case, 1 mole of gold will have exactly 6.022⋅1023 atoms of gold.
Explanation:
Answer:
[tex]\boxed {\boxed {\sf 1.62 \ mol \ Au}}[/tex]
Explanation:
We are asked to convert atoms to moles.
1. Avogadro's NumberWe know that 1 mole of any substance contains the same number of particles (atoms, molecules, formula units etc.) This is Avogadro's Number: 6.022*10²³. For this question, the particles are atoms of gold (Au).
2. Convert Atoms to MolesLet's set up a proportion using this information.
[tex]\frac {6.022*10^{23} \ atoms \ Au}{1 \ mol \ Au}[/tex]
Since we are solving for the moles in 9.75 * 10²⁴ atoms, we multiply by that number.
[tex]9.75*10^{24} \ atoms \ Au*\frac {6.022*10^{23} \ atoms \ Au}{1 \ mol \ Au}[/tex]
Flip the proportion. It will be equivalent, but the units of "atoms Au" can cancel.
[tex]9.75*10^{24} \ atoms \ Au*\frac {1 \ mol \ Au}{6.022*10^{23} \ atoms \ Au}[/tex]
[tex]9.75*10^{24} *\frac {1 \ mol \ Au}{6.022*10^{23}}[/tex]
Condense the problem into 1 fraction.
[tex]\frac {9.75*10^{24} }{6.022*10^{23}}\ mol \ Au[/tex]
[tex]1.619063434 \ mol \ Au[/tex]
3. RoundThe original measurement (9.75) has 3 significant figures. Our answer must have the same. For the number we found, that is the hundredth place.
1.619063434The 9 in the thousandth place tells us to round the 1 to a 2 in the hundredth place.
[tex]1.62 \ mol \ Au[/tex]
9.75 * 10²⁴ atoms of gold is approximately equal to 1.62 moles of gold.
Iron(II) sulfide has a molar mass of 87.91 g/mol. 50 grams of
this substance would contain about 3.011 x 1023 molecules.
TRUE
FALSE
Answer:
true
Explanation:
Answer:
[tex]\boxed {\boxed {\sf False}}[/tex]
Explanation:
We want to know if 50 grams of iron (II) sulfide contains 3.011 * 10²³ molecules. Let's calculated and check.
1. Convert Grams to MolesWe know there are 50 grams of iron (II) sulfide or FeS If we want to convert from grams to moles, we use the molar mass (mass per 1 mole). This is given to us and it is 87.91 grams per mole for this substance. Let's create a ratio.
[tex]\frac {87.91 \ g \ FeS}{ 1 \ mol \ FeS}[/tex]
We want to convert 50 grams of FeS to moles, so we multiply by this value.
[tex]50 \ g \ FeS *\frac {87.91 \ g \ FeS}{ 1 \ mol \ FeS}[/tex]
Flip the ratio so the grams of FeS cancel.
[tex]50 \ g \ FeS *\frac {1 \ mol \ FeS}{ 87.91 \ g \ FeS}[/tex]
[tex]50*\frac {1 \ mol \ FeS}{ 87.91}[/tex]
[tex]\frac {50}{ 87.91} \ mol \ FeS[/tex]
[tex]0.5687635081 \ mol \ FeS[/tex]
2. Convert Moles to Molecules1 mole of any substance contains the same number of particles (atoms, molecules, formula units, etc.). This is Avogadro's Number or 6.022 *10²³. In this case, the particles are molecules of FeS. Create another ratio.
[tex]\frac {6.022 *10^{23} \ molecules \ FeS}{ 1 \ mol \ FeS}[/tex]
We want to convert 0.5687635081 moles of FeS to molecules, so we multiply by this value.
[tex]0.5687635081 \ mol \ FeS*\frac {6.022 *10^{23} \ molecules \ FeS}{ 1 \ mol \ FeS}[/tex]
The units of moles of FeS cancel.
[tex]0.5687635081 *\frac {6.022 *10^{23} \ molecules \ FeS}{ 1 }[/tex]
[tex]0.5687635081 *{6.022 *10^{23} \ molecules \ FeS}[/tex]
[tex]3.42509385*10^{23} \ molecules \ FeS[/tex]
If we round to the thousandth place, the 0 in the tenth thousandth place tells us to leave the 5.
[tex]3.425*10^{23} \ molecules \ FeS[/tex]
50 grams of iron (II) sulfide is approximately 3.425 * 10²³ molecules, not 3.011 *10²³ so the statement is false.
What is the molarity of a solution made of 2.45 moles of LiCl in 4.75 L of solution?
Answer:
.52 M
Explanation:
moles ÷ liters = molarity
2.45 ÷ 4.75 = 0.5157894737
rounding it = .52
Consider the following reaction:
4FeS2 + 11O2 → 2Fe2O3 + 8SO2
When 28.42 grams of FeS2 reacts with 5.44 grams of O2, how many grams of SO2 are formed?
What is the limiting reactant?
What is the excess reactant?
I'm begging
Answer is D
Relatively slow rates of chemical reaction are associated with which characteristic?
A)
High temperature
B)
Low activation energy
C).
The presence of a catalyst
D)
Strong bonds in reactant molecules
Option D : Strong bonds in reactant molecules
The strong bonds in reactant molecules sometimes needs extra energy to weaken the bond and proceed the reaction. Hence, option D is correct.
What is reaction rate ?The rate of a reaction is the rate of decrease in concentration of the reactants or decrease in concentration of the reactants or increase in the concentration of the products.
The minimum energy required to overcome the barrier potential of a reaction is called its activation energy. Hence, lower the activation energy higher will be the reaction rate.
High temperature and presence of catalyst also leads to higher rate. Strong bonds in reactants needs higher energy to weaken the intermolecular force. Thus, slower the reaction rate.
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The number of molecules in 1.00 liter of O2 gas at 56◦C and 821 torr is
1. 1.83 × 1025 molec.
2. 32 molec.
3. 2.24 × 1023 molec.
4. 2.41 × 1022 molec.
5. 4 × 10−2 molec.
Answer:
2. 2.41 x 10^22 molec
Explanation:
Answer:
2. 2.41 x 10^22 molec
Explanation:
the other person said that and i got right on my quiz
What is the final volume of gas that initially occupies 2.50 L at 298 K and is subsequently heated to 321 K?
Answer: [tex]2.69\ L[/tex]
Explanation:
Given
The initial volume [tex]V_1=2.5\ L[/tex]
Temperature [tex]T_1=298\ K[/tex]
Final temperature [tex]T_2=321\ K[/tex]
Suppose pressure is constant for this process
[tex]\therefore \dfrac{V_1}{T_1}=\dfrac{V_2}{T_2}[/tex]
Insert the values
[tex]\Rightarrow \dfrac{2.5}{298}=\dfrac{V_2}{321}\\\\\Rightarrow V_2=\dfrac{321}{298}\times 2.5\\\\\Rightarrow V_2=2.69\ L[/tex]
Create a visual model of an ionic substance (salt) dissolving in water and a covalent substance (sugar) dissolving in water.
Answer:
see image
Explanation:
let me know if you have any questions
What is the chemical name for F5N3
Answer:
Fluorine azide or triazadienyl fluoride (FN3) is a yellow green gas composed of nitrogen and fluorine with formula FN3. It is counted as an interhalogen compound, as the azide functional group is termed a pseudohalogen. It resembles ClN3, BrN3, and IN3 in this respect.
Explanation:
Answer:
I think it is Fluorine not sure tho
Explanation:
Collisions only result in a reaction if the particles collide with a certain maximum energy called the activation energy of the reaction.
Answer: The statement collisions only result in a reaction if the particles collide with a certain maximum energy called the activation energy of the reaction, is false.
Explanation:
Activation energy is the minimum amount of energy required to initiate a chemical reaction.
So, when activation energy for a reaction is lower then molecules with lower energy can also participate in the reaction. As a result, more number of collisions will take place due to which an increase in the rate of reaction will takes place.
When activation energy for a reaction is larger then molecules with higher energy will not be able to participate in the reaction. As a result, less number of collisions will take place due to which a decrease in rate of reaction will occur.
Therefore, we can conclude that the statement collisions only result in a reaction if the particles collide with a certain maximum energy called the activation energy of the reaction, is false.
Answer:
true
Explanation:
particularly must collide with energy equal to or greater the
Calculate what the specific heat capacity of an unknown metal is if 394)
of heat were released when 15.0 grams of the substance at 96.0°C was
cooled to 28.0°C?
Formula Reminders
q = mCAT
q = mHvap
q = mHfus
1. 4.01 J/gºC
2. 5910 J/g°C
3. 0.387 J/g°C
Answer: The specific heat capacity of an unknown metal is [tex]0.387 J/g^{o}C[/tex].
Explanation:
Given: Heat energy = 394 J
Mass = 15 g
Initial temperature = [tex]96^{o}C[/tex]
Final temperature = [tex]28^{o}C[/tex]
Formula used is as follows.
[tex]q = m \times C \times (T_{2} - T_{1})[/tex]
where,
q = heat energy
m = mass of substance
C = specific heat capacity
[tex]T_{1}[/tex] = initial temperature
[tex]T_{2}[/tex] = final temperature
Substitute the values into above formula as follows.
[tex]q = m \times C \times (T_{2} - T_{1})\\394 J = 15 g \times C \times (28 - 96)^{o}C\\C = \frac{394 J}{15 g \times (68^{o}C)}\\= \frac{394 J}{1020 g^{o}C}\\= 0.387 J/g^{o}C[/tex]
Thus, we can conclude that the specific heat capacity of an unknown metal is [tex]0.386 J/g^{o}C[/tex].
select all that are heterogeneous mixtures.
A) soil
B) steel
C) concrete
D) kool-aid
E) open can of soda
A leaking underground storage tank or wastewater pouring into a river from a pipe would be examples of
Answer:
Water pollution.
Explanation:
This is because water pollution refers to the release or disposal of harmful substances called contaminants which contaminate water bodies which include rivers, oceans, lakes e.t.c.. These harmful substances affect aquatic organisms and make water unfit for good use. This can lead to the death if aquatic lives in the water bodies, release of bad smells and make the water bad . A leaking underground storage tank or wastewater pouring into a river from a pipe can be a source of water pollution.